Fix WebBluetooth generator to distinguish between different methods.

third_party/WebKit/LayoutTests/bluetooth/script-tests/server/get-same-object.js

 'use strict';
 promise_test(() => {
   return setBluetoothFakeAdapter('TwoHeartRateServicesAdapter')
     .then(() => requestDeviceWithKeyDown({
       filters: [{services: ['heart_rate']}],
       optionalServices: ['generic_access']}))
     .then(device => device.gatt.connect())
     .then(gattServer => Promise.all([
       gattServer.CALLS([
         getPrimaryService('heart_rate')|
         getPrimaryServices()|
         getPrimaryServices('heart_rate')[UUID]]),
       gattServer.PREVIOUS_CALL]))
     .then(services_arrays => {
       // Convert to arrays if necessary.
       for (let i = 0; i < services_arrays.length; i++) {
         services_arrays[i] = [].concat(services_arrays[i]);
       }
 
       for (let i = 1; i < services_arrays.length; i++) {
         assert_equals(services_arrays[0].length, services_arrays[i].length);
       }
 
       let base_set = new Set(services_arrays[0]);
       for (let services of services_arrays) {
         services.forEach(service => assert_true(base_set.has(service)));
       }
     });
 }, 'Calls to FUNCTION_NAME should return the same object.');